上颌恒侧切牙牙冠解剖变异调查

Crown shape variations of permanent maxillary lateral incisors

目的:揭示上颌恒侧切牙牙冠变异的解剖特点及发生规律。方法:对乌鲁木齐市一个汉族中学生人群(3 422人)进行口腔检查,调查上颌侧切牙的牙冠变异情况,记录畸形舌侧尖、过小牙及侧切牙先天缺失的发生状况。统计各项变异的发生率。双侧相关性采用Kendall检验。结果:畸形舌侧尖的个体发生率为1.14%(39/3 422),牙齿发生率为0.89%(61/6 832),双侧共同发生率为56.41%(22/39)。过小牙个体发生率为3.10%(106/3 422),牙齿发生率为2.33%(159/6 832),双侧共同发生率为50%(53/106)。上颌侧切牙先天缺失的个体发生率为0.26%(9/3 422),双侧共同发生率为33.33%(3/9)。畸形舌侧尖、过小牙及先天缺失左右侧发生的相关系数tau分别为0.724,0.682和0.520(P<0.05)。以上变异男女组间以及左右组间差异均无统计学意义(P>0.05)。结论:上颌侧切牙畸形舌侧尖、过小牙及先天缺失在汉族人中发生率均较低,但双侧共同发生率相对较高。

AIM ： To investigate the anatomical features and occurrence patterns of the crown variations of permanent maxillary lateral incisors. METHODS： Direct intraoral examination was conducted on 3 422 HaM Chinese middle school students. The occurrence of talon cusp, microdontia and congenital anodontia of the maxillary permanent lateral incisors were recorded, and the occurrence rate of each type of variations was calculated. Correlations in the ex- pression of the trait between bilateral antimeric teeth were evaluated by Kendall test. RESULTS： The incidences of talon cusp were 1.14% （39/3 422 individuals） and 0.89% （61/6 832 teeth）, and the bilateral concurrence rate was 56.41% （22/39）. The incidences of microdontia were 3.10% （106/3 422 individuals） and 2.32% （159/6 832 teeth）, and the bilateral concurrence rate was 50.00% （53/106）. The prevalence of congenital anodontia was 0.26% （9/3 422 individuals） and the bilateral concurrence rate was 33.33 % （3/9）. Kendall tau rank correlation coefficient was 0.724,0. 682 and 0. 520 for talon cusp, microdontia and congenital anodontia, repectively （ P 〈 0.05 ）. Statisti- cally significant differences were not found between both genders and both sides （ P 〉 0.05）. CONCLUSION ： The frequencies of talon cusp, microdontia and congenital anodontia in maxillary lateral incisors are very low in the HaM Chinese people, but the bilateral concurrence rates are relatively much higher.